libbctoolbox1: update would uninstall kde-full, kde-standard packages on Focal

This is the result of starting some upgrades in early April that are required to build newer Linphone versions, with bctoolbox being one such upgrade, but not actually completing all required upgrades yet. The libmediastreamer-{base,voip}10 libraries as built in official Focal repositories specifically require libbctoolbox1 >= 0.6.0 and << 0.7.0 presumably due newer versions of libbctoolbox1 being ABI incompatible without doing a rebuild of the mediastreamer2 source package.

So a rebuild of mediastreamer2 2.16.1 (default version in Focal) has now been done against backports of newer bctoolbox, bzrtp, and ortp libraries from Linphone (all v4.4.13) at ppa:savoury1/multimedia. This means that new libbctoolbox1 4.4.13 should be able to install successfully for Focal users, with libmediastreamer-{base,voip}10 (rebuilt to now depend on libbctoolbox >= 4.4.0 and << 4.5.0) also being upgraded as part of the process of installing new libbctoolbox1.

Unfortunately, the problem has not yet been resolved. It seems to hinge on libortp15 vs libortp13 (the former supposedly replaces the latter but does not (cannot?) come with the same "provides"):

[2022-05-29T07:51:08+0200] root@desktop01:~# LANG=C apt install libbctoolbox1
Reading package lists... Done
[…]
The following additional packages will be installed:
  libbzrtp0 libmediastreamer-base10 libmediastreamer-voip10 libortp15
The following packages will be REMOVED:
  kde-full kde-standard kdenetwork kopete libortp13
The following NEW packages will be installed:
  libortp15
The following packages will be upgraded:
  libbctoolbox1 libbzrtp0 libmediastreamer-base10 libmediastreamer-voip10
4 upgraded, 1 newly installed, 5 to remove and 1 not upgraded.
Need to get 471 kB of archives.
After this operation, 15.4 MB disk space will be freed.
Do you want to continue? [Y/n] N
Abort.
[2022-05-29T07:51:49+0200] root@desktop01:~# LANG=C apt depends libortp13
libortp13
  Depends: libbctoolbox1 (>= 0.6.0)
  Depends: libbctoolbox1 (<< 0.7.0)
  Depends: libc6 (>= 2.27)
[2022-05-29T07:52:06+0200] root@desktop01:~# LANG=C apt depends kopete 2>/dev/null | grep libortp
  Depends: libortp13 (>= 1:1.0.1)
[2022-05-29T07:52:11+0200] root@desktop01:~# LANG=C apt depends kde-standard 2>/dev/null | grep kopete
  Depends: kopete (>= 4:17.08.3)
[2022-05-29T07:53:13+0200] root@desktop01:~# LANG=C apt depends libmediastreamer-base10
libmediastreamer-base10
  Depends: libbctoolbox1 (>= 4.4.0)
  Depends: libbctoolbox1 (<< 4.5.0)
  Depends: libc6 (>= 2.14)
  Depends: libortp15 (>= 1:4.4.0)
  Depends: libortp15 (<< 1:4.5.0)

[2022-05-29T07:57:26+0200] root@desktop01:~# LANG=C apt policy libbctoolbox1
libbctoolbox1:
  Installed: 0.6.0-2build3
  Candidate: 4.4.13-3build1~20.04.sav0
  Version table:
     4.4.13-3build1~20.04.sav0 500
        500 http://ppa.launchpad.net/savoury1/multimedia/ubuntu focal/main amd64 Packages
 *** 0.6.0-2build3 500
        500 http://de.archive.ubuntu.com/ubuntu focal/universe amd64 Packages
        100 /var/lib/dpkg/status
[2022-05-29T07:57:44+0200] root@desktop01:~#

Without rebuilding kde* (does not really sound like an option), the only alternative way forward (if libortp15 cannot be made "compatible" with libortp13) would likely be for libmediastreamer*10 to accept/depend on either libortp13 or libortp15. Not sure whether this can be accomplished "downstream" either.

On second thought, updating *kopete* should be enough w/o having to touch kde* (whether this opens another can of worms I cannot say):

[2022-05-29T07:57:44+0200] root@desktop01:~# LANG=C apt policy kopete
kopete:
  Installed: 4:19.12.3-0ubuntu1
  Candidate: 4:19.12.3-0ubuntu1
  Version table:
 *** 4:19.12.3-0ubuntu1 500
        500 http://de.archive.ubuntu.com/ubuntu focal/universe amd64 Packages
        100 /var/lib/dpkg/status

First it is good to be clear about a couple of details relative to how Debian/Ubuntu packaging works with various library versions. The packaging system is designed to generally allow co-installation of multiple versions of the same library without any issue whatsoever. However, these Linphone packages have unusual version constraints with an upper limit as well, which is not the norm for almost any libraries. This means that in this instance libortp13 cannot be co-installed with libortp15 due the earlier libortp13 still having the libbctoolbox1 << 0.7.0 restriction.

So the continuing issue here is to do with the kopete package specifically, which I did not realise is a dependency of the KDE meta-packages you mentioned in the original bug report, and that is why the issue is not fully resolved yet. Due kopete depending on libortp13 and due this unusual situation with very restrictive versioning for the libbctoolbox1 dependency it will indeed require rebuilding kopete against newer libortp15 for the issue to be fully resolved. This will be done, the rebuilt kopete will be uploaded to ppa:savoury1/multimedia, and then this bug will be updated once the kopete rebuild is published.

Also, if you happen to want newer Qt/KDE packages than Focal default you can look at ppa:savoury1/qt-5-15 [1] and ppa:savoury1/kde-5-80 [2] which have backports of Qt 5.15.2 and compatible KDE packages. Interestingly, the newer kde-standard package backported to the mentioned KDE PPA no longer depends on kopete due kopete not being in Debian, so kopete was not part of the backported suite of KDE packages so far. However, it will now be also added to ppa:savoury1/kde-5-80 for users such as yourself who use that software.

[1] https://launchpad.net/~savoury1/+archive/ubuntu/qt-5-15
[2] https://launchpad.net/~savoury1/+archive/ubuntu/kde-5-80

Rebuild of kopete 19.12.3 against new bctoolbox/ortp 4.4.13 for Ubuntu 20.04 Focal (package version 4:19.12.3-0ubuntu1+20.04.sav0) is now published at ppa:savoury1/multimedia which should fully resolve this upgrade issue related to these various Linphone libraries!

It worked! Thanks a lot!